1. Field of the Invention
The present invention relates to an exhaust gas recirculation apparatus configured to open and close a valve by operation of an actuator to return or recirculate a part of exhaust gas discharged from an engine to an intake system.
2. Related Art
Heretofore, a part of exhaust gas discharged from an engine is recirculated to an intake system. An exhaust gas recirculation apparatus is thus used to control recirculating the exhaust gas to the intake system. In this exhaust gas recirculation apparatus, for example, the actuator is drivingly controlled to move up and down a valve provided at one end of a drive shaft to adjust an opening degree of the valve, thereby controlling an amount of exhaust gas to be returned to the intake system.
As one example of such an exhaust gas recirculation apparatus, Patent Document 1 discloses an exhaust gas recirculation apparatus configured to prevent inflow of exhaust gas to an intake passage while an actuator is not driven and a valve part is closed by an urging force of a spring.